// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2008 Gael Guennebaud <gael.guennebaud@inria.fr>
// Copyright (C) 2006-2010 Benoit Jacob <jacob.benoit.1@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#ifndef EIGEN_BLOCK_H
#define EIGEN_BLOCK_H

namespace Eigen {

namespace internal {
    template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel> struct traits<Block<XprType, BlockRows, BlockCols, InnerPanel>> : traits<XprType>
    {
        typedef typename traits<XprType>::Scalar Scalar;
        typedef typename traits<XprType>::StorageKind StorageKind;
        typedef typename traits<XprType>::XprKind XprKind;
        typedef typename ref_selector<XprType>::type XprTypeNested;
        typedef typename remove_reference<XprTypeNested>::type _XprTypeNested;
        enum
        {
            MatrixRows = traits<XprType>::RowsAtCompileTime,
            MatrixCols = traits<XprType>::ColsAtCompileTime,
            RowsAtCompileTime = MatrixRows == 0 ? 0 : BlockRows,
            ColsAtCompileTime = MatrixCols == 0 ? 0 : BlockCols,
            MaxRowsAtCompileTime = BlockRows == 0 ? 0 : RowsAtCompileTime != Dynamic ? int(RowsAtCompileTime) : int(traits<XprType>::MaxRowsAtCompileTime),
            MaxColsAtCompileTime = BlockCols == 0 ? 0 : ColsAtCompileTime != Dynamic ? int(ColsAtCompileTime) : int(traits<XprType>::MaxColsAtCompileTime),

            XprTypeIsRowMajor = (int(traits<XprType>::Flags) & RowMajorBit) != 0,
            IsRowMajor =
                (MaxRowsAtCompileTime == 1 && MaxColsAtCompileTime != 1) ? 1 : (MaxColsAtCompileTime == 1 && MaxRowsAtCompileTime != 1) ? 0 : XprTypeIsRowMajor,
            HasSameStorageOrderAsXprType = (IsRowMajor == XprTypeIsRowMajor),
            InnerSize = IsRowMajor ? int(ColsAtCompileTime) : int(RowsAtCompileTime),
            InnerStrideAtCompileTime =
                HasSameStorageOrderAsXprType ? int(inner_stride_at_compile_time<XprType>::ret) : int(outer_stride_at_compile_time<XprType>::ret),
            OuterStrideAtCompileTime =
                HasSameStorageOrderAsXprType ? int(outer_stride_at_compile_time<XprType>::ret) : int(inner_stride_at_compile_time<XprType>::ret),

            // FIXME, this traits is rather specialized for dense object and it needs to be cleaned further
            FlagsLvalueBit = is_lvalue<XprType>::value ? LvalueBit : 0,
            FlagsRowMajorBit = IsRowMajor ? RowMajorBit : 0,
            Flags = (traits<XprType>::Flags & (DirectAccessBit | (InnerPanel ? CompressedAccessBit : 0))) | FlagsLvalueBit | FlagsRowMajorBit,
            // FIXME DirectAccessBit should not be handled by expressions
            //
            // Alignment is needed by MapBase's assertions
            // We can sefely set it to false here. Internal alignment errors will be detected by an eigen_internal_assert in the respective evaluator
            Alignment = 0
        };
    };

    template <typename XprType,
              int BlockRows = Dynamic,
              int BlockCols = Dynamic,
              bool InnerPanel = false,
              bool HasDirectAccess = internal::has_direct_access<XprType>::ret>
    class BlockImpl_dense;

}  // end namespace internal

template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel, typename StorageKind> class BlockImpl;

/** \class Block
  * \ingroup Core_Module
  *
  * \brief Expression of a fixed-size or dynamic-size block
  *
  * \tparam XprType the type of the expression in which we are taking a block
  * \tparam BlockRows the number of rows of the block we are taking at compile time (optional)
  * \tparam BlockCols the number of columns of the block we are taking at compile time (optional)
  * \tparam InnerPanel is true, if the block maps to a set of rows of a row major matrix or
  *         to set of columns of a column major matrix (optional). The parameter allows to determine
  *         at compile time whether aligned access is possible on the block expression.
  *
  * This class represents an expression of either a fixed-size or dynamic-size block. It is the return
  * type of DenseBase::block(Index,Index,Index,Index) and DenseBase::block<int,int>(Index,Index) and
  * most of the time this is the only way it is used.
  *
  * However, if you want to directly maniputate block expressions,
  * for instance if you want to write a function returning such an expression, you
  * will need to use this class.
  *
  * Here is an example illustrating the dynamic case:
  * \include class_Block.cpp
  * Output: \verbinclude class_Block.out
  *
  * \note Even though this expression has dynamic size, in the case where \a XprType
  * has fixed size, this expression inherits a fixed maximal size which means that evaluating
  * it does not cause a dynamic memory allocation.
  *
  * Here is an example illustrating the fixed-size case:
  * \include class_FixedBlock.cpp
  * Output: \verbinclude class_FixedBlock.out
  *
  * \sa DenseBase::block(Index,Index,Index,Index), DenseBase::block(Index,Index), class VectorBlock
  */
template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
class Block : public BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, typename internal::traits<XprType>::StorageKind>
{
    typedef BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, typename internal::traits<XprType>::StorageKind> Impl;

public:
    //typedef typename Impl::Base Base;
    typedef Impl Base;
    EIGEN_GENERIC_PUBLIC_INTERFACE(Block)
    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(Block)

    typedef typename internal::remove_all<XprType>::type NestedExpression;

    /** Column or Row constructor
      */
    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Block(XprType& xpr, Index i) : Impl(xpr, i)
    {
        eigen_assert((i >= 0) && (((BlockRows == 1) && (BlockCols == XprType::ColsAtCompileTime) && i < xpr.rows()) ||
                                  ((BlockRows == XprType::RowsAtCompileTime) && (BlockCols == 1) && i < xpr.cols())));
    }

    /** Fixed-size constructor
      */
    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Block(XprType& xpr, Index startRow, Index startCol) : Impl(xpr, startRow, startCol)
    {
        EIGEN_STATIC_ASSERT(RowsAtCompileTime != Dynamic && ColsAtCompileTime != Dynamic, THIS_METHOD_IS_ONLY_FOR_FIXED_SIZE)
        eigen_assert(startRow >= 0 && BlockRows >= 0 && startRow + BlockRows <= xpr.rows() && startCol >= 0 && BlockCols >= 0 &&
                     startCol + BlockCols <= xpr.cols());
    }

    /** Dynamic-size constructor
      */
    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE Block(XprType& xpr, Index startRow, Index startCol, Index blockRows, Index blockCols)
        : Impl(xpr, startRow, startCol, blockRows, blockCols)
    {
        eigen_assert((RowsAtCompileTime == Dynamic || RowsAtCompileTime == blockRows) && (ColsAtCompileTime == Dynamic || ColsAtCompileTime == blockCols));
        eigen_assert(startRow >= 0 && blockRows >= 0 && startRow <= xpr.rows() - blockRows && startCol >= 0 && blockCols >= 0 &&
                     startCol <= xpr.cols() - blockCols);
    }
};

// The generic default implementation for dense block simplu forward to the internal::BlockImpl_dense
// that must be specialized for direct and non-direct access...
template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
class BlockImpl<XprType, BlockRows, BlockCols, InnerPanel, Dense> : public internal::BlockImpl_dense<XprType, BlockRows, BlockCols, InnerPanel>
{
    typedef internal::BlockImpl_dense<XprType, BlockRows, BlockCols, InnerPanel> Impl;
    typedef typename XprType::StorageIndex StorageIndex;

public:
    typedef Impl Base;
    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl)
    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl(XprType& xpr, Index i) : Impl(xpr, i) {}
    EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl(XprType& xpr, Index startRow, Index startCol) : Impl(xpr, startRow, startCol) {}
    EIGEN_DEVICE_FUNC
    EIGEN_STRONG_INLINE BlockImpl(XprType& xpr, Index startRow, Index startCol, Index blockRows, Index blockCols)
        : Impl(xpr, startRow, startCol, blockRows, blockCols)
    {
    }
};

namespace internal {

    /** \internal Internal implementation of dense Blocks in the general case. */
    template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel, bool HasDirectAccess>
    class BlockImpl_dense : public internal::dense_xpr_base<Block<XprType, BlockRows, BlockCols, InnerPanel>>::type
    {
        typedef Block<XprType, BlockRows, BlockCols, InnerPanel> BlockType;
        typedef typename internal::ref_selector<XprType>::non_const_type XprTypeNested;

    public:
        typedef typename internal::dense_xpr_base<BlockType>::type Base;
        EIGEN_DENSE_PUBLIC_INTERFACE(BlockType)
        EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl_dense)

        // class InnerIterator; // FIXME apparently never used

        /** Column or Row constructor
      */
        EIGEN_DEVICE_FUNC
        inline BlockImpl_dense(XprType& xpr, Index i)
            : m_xpr(xpr),
              // It is a row if and only if BlockRows==1 and BlockCols==XprType::ColsAtCompileTime,
              // and it is a column if and only if BlockRows==XprType::RowsAtCompileTime and BlockCols==1,
              // all other cases are invalid.
              // The case a 1x1 matrix seems ambiguous, but the result is the same anyway.
              m_startRow((BlockRows == 1) && (BlockCols == XprType::ColsAtCompileTime) ? i : 0),
              m_startCol((BlockRows == XprType::RowsAtCompileTime) && (BlockCols == 1) ? i : 0), m_blockRows(BlockRows == 1 ? 1 : xpr.rows()),
              m_blockCols(BlockCols == 1 ? 1 : xpr.cols())
        {
        }

        /** Fixed-size constructor
      */
        EIGEN_DEVICE_FUNC
        inline BlockImpl_dense(XprType& xpr, Index startRow, Index startCol)
            : m_xpr(xpr), m_startRow(startRow), m_startCol(startCol), m_blockRows(BlockRows), m_blockCols(BlockCols)
        {
        }

        /** Dynamic-size constructor
      */
        EIGEN_DEVICE_FUNC
        inline BlockImpl_dense(XprType& xpr, Index startRow, Index startCol, Index blockRows, Index blockCols)
            : m_xpr(xpr), m_startRow(startRow), m_startCol(startCol), m_blockRows(blockRows), m_blockCols(blockCols)
        {
        }

        EIGEN_DEVICE_FUNC inline Index rows() const { return m_blockRows.value(); }
        EIGEN_DEVICE_FUNC inline Index cols() const { return m_blockCols.value(); }

        EIGEN_DEVICE_FUNC
        inline Scalar& coeffRef(Index rowId, Index colId)
        {
            EIGEN_STATIC_ASSERT_LVALUE(XprType)
            return m_xpr.coeffRef(rowId + m_startRow.value(), colId + m_startCol.value());
        }

        EIGEN_DEVICE_FUNC
        inline const Scalar& coeffRef(Index rowId, Index colId) const
        {
            return m_xpr.derived().coeffRef(rowId + m_startRow.value(), colId + m_startCol.value());
        }

        EIGEN_DEVICE_FUNC
        EIGEN_STRONG_INLINE const CoeffReturnType coeff(Index rowId, Index colId) const
        {
            return m_xpr.coeff(rowId + m_startRow.value(), colId + m_startCol.value());
        }

        EIGEN_DEVICE_FUNC
        inline Scalar& coeffRef(Index index)
        {
            EIGEN_STATIC_ASSERT_LVALUE(XprType)
            return m_xpr.coeffRef(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index), m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
        }

        EIGEN_DEVICE_FUNC
        inline const Scalar& coeffRef(Index index) const
        {
            return m_xpr.coeffRef(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index), m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
        }

        EIGEN_DEVICE_FUNC
        inline const CoeffReturnType coeff(Index index) const
        {
            return m_xpr.coeff(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index), m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
        }

        template <int LoadMode> inline PacketScalar packet(Index rowId, Index colId) const
        {
            return m_xpr.template packet<Unaligned>(rowId + m_startRow.value(), colId + m_startCol.value());
        }

        template <int LoadMode> inline void writePacket(Index rowId, Index colId, const PacketScalar& val)
        {
            m_xpr.template writePacket<Unaligned>(rowId + m_startRow.value(), colId + m_startCol.value(), val);
        }

        template <int LoadMode> inline PacketScalar packet(Index index) const
        {
            return m_xpr.template packet<Unaligned>(m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index),
                                                    m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0));
        }

        template <int LoadMode> inline void writePacket(Index index, const PacketScalar& val)
        {
            m_xpr.template writePacket<Unaligned>(
                m_startRow.value() + (RowsAtCompileTime == 1 ? 0 : index), m_startCol.value() + (RowsAtCompileTime == 1 ? index : 0), val);
        }

#ifdef EIGEN_PARSED_BY_DOXYGEN
        /** \sa MapBase::data() */
        EIGEN_DEVICE_FUNC inline const Scalar* data() const;
        EIGEN_DEVICE_FUNC inline Index innerStride() const;
        EIGEN_DEVICE_FUNC inline Index outerStride() const;
#endif

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const typename internal::remove_all<XprTypeNested>::type& nestedExpression() const { return m_xpr; }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE XprType& nestedExpression() { return m_xpr; }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR StorageIndex startRow() const EIGEN_NOEXCEPT { return m_startRow.value(); }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR StorageIndex startCol() const EIGEN_NOEXCEPT { return m_startCol.value(); }

    protected:
        XprTypeNested m_xpr;
        const internal::variable_if_dynamic<StorageIndex, (XprType::RowsAtCompileTime == 1 && BlockRows == 1) ? 0 : Dynamic> m_startRow;
        const internal::variable_if_dynamic<StorageIndex, (XprType::ColsAtCompileTime == 1 && BlockCols == 1) ? 0 : Dynamic> m_startCol;
        const internal::variable_if_dynamic<StorageIndex, RowsAtCompileTime> m_blockRows;
        const internal::variable_if_dynamic<StorageIndex, ColsAtCompileTime> m_blockCols;
    };

    /** \internal Internal implementation of dense Blocks in the direct access case.*/
    template <typename XprType, int BlockRows, int BlockCols, bool InnerPanel>
    class BlockImpl_dense<XprType, BlockRows, BlockCols, InnerPanel, true> : public MapBase<Block<XprType, BlockRows, BlockCols, InnerPanel>>
    {
        typedef Block<XprType, BlockRows, BlockCols, InnerPanel> BlockType;
        typedef typename internal::ref_selector<XprType>::non_const_type XprTypeNested;
        enum
        {
            XprTypeIsRowMajor = (int(traits<XprType>::Flags) & RowMajorBit) != 0
        };

    public:
        typedef MapBase<BlockType> Base;
        EIGEN_DENSE_PUBLIC_INTERFACE(BlockType)
        EIGEN_INHERIT_ASSIGNMENT_OPERATORS(BlockImpl_dense)

        /** Column or Row constructor
      */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl_dense(XprType& xpr, Index i)
            : Base(xpr.data() + i * (((BlockRows == 1) && (BlockCols == XprType::ColsAtCompileTime) && (!XprTypeIsRowMajor)) ||
                                             ((BlockRows == XprType::RowsAtCompileTime) && (BlockCols == 1) && (XprTypeIsRowMajor)) ?
                                         xpr.innerStride() :
                                         xpr.outerStride()),
                   BlockRows == 1 ? 1 : xpr.rows(),
                   BlockCols == 1 ? 1 : xpr.cols()),
              m_xpr(xpr), m_startRow((BlockRows == 1) && (BlockCols == XprType::ColsAtCompileTime) ? i : 0),
              m_startCol((BlockRows == XprType::RowsAtCompileTime) && (BlockCols == 1) ? i : 0)
        {
            init();
        }

        /** Fixed-size constructor
      */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl_dense(XprType& xpr, Index startRow, Index startCol)
            : Base(xpr.data() + xpr.innerStride() * (XprTypeIsRowMajor ? startCol : startRow) + xpr.outerStride() * (XprTypeIsRowMajor ? startRow : startCol)),
              m_xpr(xpr), m_startRow(startRow), m_startCol(startCol)
        {
            init();
        }

        /** Dynamic-size constructor
      */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl_dense(XprType& xpr, Index startRow, Index startCol, Index blockRows, Index blockCols)
            : Base(xpr.data() + xpr.innerStride() * (XprTypeIsRowMajor ? startCol : startRow) + xpr.outerStride() * (XprTypeIsRowMajor ? startRow : startCol),
                   blockRows,
                   blockCols),
              m_xpr(xpr), m_startRow(startRow), m_startCol(startCol)
        {
            init();
        }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE const typename internal::remove_all<XprTypeNested>::type& nestedExpression() const EIGEN_NOEXCEPT
        {
            return m_xpr;
        }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE XprType& nestedExpression() { return m_xpr; }

        /** \sa MapBase::innerStride() */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR Index innerStride() const EIGEN_NOEXCEPT
        {
            return internal::traits<BlockType>::HasSameStorageOrderAsXprType ? m_xpr.innerStride() : m_xpr.outerStride();
        }

        /** \sa MapBase::outerStride() */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR Index outerStride() const EIGEN_NOEXCEPT
        {
            return internal::traits<BlockType>::HasSameStorageOrderAsXprType ? m_xpr.outerStride() : m_xpr.innerStride();
        }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR StorageIndex startRow() const EIGEN_NOEXCEPT { return m_startRow.value(); }

        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE EIGEN_CONSTEXPR StorageIndex startCol() const EIGEN_NOEXCEPT { return m_startCol.value(); }

#ifndef __SUNPRO_CC
        // FIXME sunstudio is not friendly with the above friend...
        // META-FIXME there is no 'friend' keyword around here. Is this obsolete?
    protected:
#endif

#ifndef EIGEN_PARSED_BY_DOXYGEN
        /** \internal used by allowAligned() */
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE BlockImpl_dense(XprType& xpr, const Scalar* data, Index blockRows, Index blockCols)
            : Base(data, blockRows, blockCols), m_xpr(xpr)
        {
            init();
        }
#endif

    protected:
        EIGEN_DEVICE_FUNC EIGEN_STRONG_INLINE void init()
        {
            m_outerStride = internal::traits<BlockType>::HasSameStorageOrderAsXprType ? m_xpr.outerStride() : m_xpr.innerStride();
        }

        XprTypeNested m_xpr;
        const internal::variable_if_dynamic<StorageIndex, (XprType::RowsAtCompileTime == 1 && BlockRows == 1) ? 0 : Dynamic> m_startRow;
        const internal::variable_if_dynamic<StorageIndex, (XprType::ColsAtCompileTime == 1 && BlockCols == 1) ? 0 : Dynamic> m_startCol;
        Index m_outerStride;
    };

}  // end namespace internal

}  // end namespace Eigen

#endif  // EIGEN_BLOCK_H
